Grinding and polishing



Nov. 3, 1959 H. WHITESELL GRINDING AND POLISHING Filed Aug. 6, 1957HarryWhH'ese H,

Unite States. Patent GRINDING AND POLISHING Harry Wlu'tesell, Chicago,Ill.

Application August 6, 1957, Serial No. 676,620

12 Claims. (Cl. 51-267) This invention relates to improvements ingrinding and polishing, and the like. More particularly, the inventionrelates to improvements in grinding and polishing operations in whichthe abrasive surface against which the work being treated is held, ismoved at a comparatively high rate of speed, although it will alsobecome apparent that said improvements are not limited to high speedsurface operations. Such speeds as presently being practised may be ofthe order of ten to twelve thousand feet per minute, or even higher.Likewise, the rotative speeds of the wheels carrying, or over which theabrasive surface travels must be of corresponding values, taking accountof the wheel sizes used. Thus, in the case of a wheel of diameter ofeighteen inches and having a peripheral speed of twelve thousand feetper minute the rotative speed will be of the order of 2545 r.p.m. Thecentrifugal forces developed at such speeds and with such wheel sizesare very large. The features ofinvention herein disclosed may beadvantageously used in connection with such high speed operations, butsaid features are also usable in connection with much lower speedoperations as for example, 1000 ft./min., or less.

The features of the present invention are useful in connection withoperations in which the abrading is produced by direct contact of thework with the surface of an abrading wheel, in which type of operationsuch wheel surface is provided with abrasive, either as a surfaceapplication or as a component of the wheel material itself. The featuresof the present invention are also applicable to operations in which anabrasive belt is travelled over a contact wheel, the work being heldagainst the surface of such travelling belt, generally at a locationwhere such belt is riding over the wheel surface. In the case of suchbelt type operation the abrasive material carried by such travellingbelt has a linear speed around the wheel perimeter equal to the beltspeed.

It has been found desirable, and in many cases necessary to deliver tothe travelling abrasive surface some form of liquid so that the abrasiveparticles are wetted thereby at the cutting area. Due to the high rateof travel of such abrasive surface great difficulty has been encounteredin actually delivering such liquid agent into wetting contact with thebelt or wheel surface, or in keeping such liquid agent on such surfaceif it has, in fact actually been possible to truly effect wettingcontact thereof with such surface. A prime difficulty in effectingactual delivery of such liquid agent to the travelling surface hasarisen from the following conditions:

A surface travelling at high speed produces a drag on the surroundingatmosphere. Such drag depends largely on the smoothness of thetravelling surface, but the rate of travel is a prime factor inproducing such drag. As the rate of travel is increased such dragincreases rapidly. Accordingly, it has been found that at the necessaryspeeds for abrasion such drag becomes high. The very fact that thesurface is non-smooth and of an abrasive nature multiplies the drag, andthus produces a layer or film of air 2,910,811 Patented Nov. 3, 1959travelling along and with the abrasive surface. The very rate of travelof such film of air brings such film to a condition of high resistanceto penetration of such film by any object seeking to penetrate it forproducing actual contact with the travelling abrasive surface.Additionally, any liquid material which might penetrate such rapidlytravelling film would then encounter the roughened abrasive surface withcorresponding violent contacts of the liquid particles with the abrasivesurface particles. Such high velocity contacts would also tend to driveany droplets of the liquid away from the very surface which they wereintended to wet. Furthermore, the centrifugal forces developed by travelat such linear rates as suggested above, and with the angular velocitiesproduced at the wheel periphery are such that any droplets which mayhave reached the abrasive particles would be expelled from the abrasivesurface as a mist or fine cloud.

For the foregoing and other reasons it has been found practicallyimpossible to maintain a wetted condition of the abrasive surface byconventional operations which primarily depend on directing the liquidbody against the travelling surface or against the air film whichprevents actual substantial contact of such wetting material with thesurface intended to be wetted.

it is a prime object of the present invention to provide a method andthe means to ensure effective delivery of the liquid material to theabrasive surface and to also ensure that such material, so delivered tosuch surface will retain its effective adherence to the abrasiveparticles and perform its intended function in conjunction with theabrasive particles during the abrading operation. The followingoperations are also noted in connection with the foregoing:

When the belt type operation is used it is necessary to provide an idlerwheel, the belt travelling over such idler wheel and the contact wheel.Such idller wheel thus used, is generally crowned and adjustable so thatthe tracking of the belt over the contact wheel may be controlled.Nevertheless, it frequently is found ditficult to effectively controlsuch tracking of the contact wheel, especially when the belt is ofnarrow Width, such as a few inches. This is especially true in the caseof contact wheels which are not crowned but are provided with flexibleperipheral surfaces. It is also true in the case of contact wheels whichare provided with contoured surfaces to conform to the contour of thework being treated. The present improvements provide a supplementalcontrol of the belt during its travel over the contact wheel. Suchsupplemental control of the belt travel is provided at a location veryclose to the point of entry of belt travel onto the contact wheel.

My present improvements include the provision of a supplemental wheelriding on and pressed against the belt on that run of the belttravelling towards the contact wheel, and close to the point of entry ofthe belt onto such contact wheel. This supplemental wheel is preferablycrowned so that it depresses the central portion of the travelling beltlower than the edges of such belt with consequent production of a slightvalley facing outwardly away from the axis of contact wheel rotation.Then, as the belt enters onto the surface of the contact wheel suchsight valley is flattened out, or in case the contact wheel iscontoured, an actual reversal of the deflection of the central portionof the belt may be produced, changing such belt from an outwardly facingvalley to an inwardly facing valley during the travel over the contactwheel. Such supplemental wheel serves to produce an added control of thebelt travel, making it possible to better control the tracking asexplained above.

Next, I provide means to introduce the liquid body against the beltsurface directly in front of the location of contact of suchsupplemental wheel with the belt, or with the surface of the abrasivewheel in cases where the abrasive is carried directly by or isimpregnated into the material of the wheel surface without interpositionof the belt, or in cases where the wheel itself is formed of abrasivematerial such as vitreous abrasive material. Such introduction of theliquid at such location is conveniently done by a sprayingand/ordripping operation, preferably with a rather high pressurespraydirected closely towards the location of engagement of thesupplemental wheel with the belt or wheel surface. If needed, a suitableshield may' be provided around the supplemental wheel, such shieldcoming close to the belt or Wheel surface at each side of thesupplemental wheel, leaving only sufficient opening between the end ofsuch shield'and the belt or wheel surface to permit the liquid body tobe definitely introduced against the intended surface justbefore suchsurface is physically contacted by such supplemental wheel. Thereby theliquid body is carried almost immediately to the location of strongpressure between such supplemental wheel and the belt or the wheelssurface, with immediate strong pressure of such liquid body against theabrasive surface itself. Such strong pressure will then effect drive ofthe liquid body well into the interstices between the abrasive particlesof the. abrasive surface, thus ensuring effective wetting of suchparticles by a film of such liquid body material. Having thuseffectively deposited such film of the liquid' body onto the abrasiveparticles such film will adhere strongly to such particles andefiectively resist outward throw by the centrifugal forces developedduring radial acceleration around the wheel surface or the surface ofthe belt. When the surface of the wheel is of abrasive nature and nobelt is used, the surface of such wheel being flexible as in the case ofa bufiing wheel, by introducing loose abrasive material onto thesupplemental wheel said abrasive material will be strongly impregnatedinto such flexible buffing wheel.

A further effect of the crowning of the supplemental wheel is asfollows:

Any tendency for the applied liquid to concentrate at a specificlocation across the width of the belt or of the abrasive wheel isimmediately resisted and counteracted by such crowning of thesupplemental wheel, since the effect of such crowning is to force atleast some of the trapped liquid body laterally towards the edges orother areas of the belt or of the abrasive wheel, and with production ofa substantially even distribution of the liquid body over the entirewidth of the abrasive carrier. The pressure of the supplemental wheelagainst the abrasive surface serves to drive the liquid body fullybetween the abrasive particles since the yieldable or flexible surfaceof the supplemental wheel ensures effective pressure of such yieldableor flexible wheel surface deep between the abrasive particles carried bysuch abrasive surface. This ensures wetting of the full exposed surfacesof the abrasive particles instead of merely their extreme end portionsas would otherwise be wetted. Thus the present improve ments serve toensure effective wetting of the full exposed surfaces of the abrasiveparticles.

It is also noted that the film of air carried along with the belt at itssurface, or with the periphery of the wheel in case no belt is used,travels directly into the zone of contact between the supplemental wheeland the abrasive surface, which zone is rapidly closing to zerothickness as the location of engagement between the supplemental wheeland the abrasive surface is reached. Thus such film of interfering airis completely eliminated at the location where the liquid body is to beintroduced and carried into the spaces between the abrasive particles.Such film of air is actually turned laterally to the sides of theabrasive carrier, and thus aids in securing desired distribution of theliquid body to all widths of such abrasive surface. This is adistinctive feature of my method and. means. In connection with theforegoing it is also noted that the air of the film above referred totends to compress into the narrowing space between the abrasive surfaceand the supplemental wheel, thus producing a cushion against which thefurther oncoming air of the film is received. Thereby such oncoming airfilm is actually slowed down just before reaching the location ofclosure between the supplemental wheel and the abrasive surface. Thisslowing down also greatly reduces the opposition to penetration of suchair film by the liquid body. Such slowing down of the air film alsoensures a driving action of the particles of liquid in forwardcontinuing direction clear to the location of actual contact between thesupplemental wheel and the abrasive surface with which contact of thesupplemental wheel is made. This driving action is due to the inertia ofsuch liquid particles whose specific gravity is many times as great asthat of the air film. All of these factors act to make it possible toproduce the desired wetting of the abrasive particles by use of thefeatures of my present invention.

A further important feature and object of my present invention is asfollows:

During use the abrasive surface receives the material removed from thework body as well as various other foreign ingredients. Such otherforeign ingredients may include paint removed from the work body,various oxides and salts and small, almost microscopic chips cut fromthe work body; Additionally, minute particles of the abrasive particlesthemselves are broken off and become a portion of the detritus. All suchdetritus material becomes packed against and into the surface of theabrasive carrier and around the abrasive particles of such carrier. As aconsequence the abrading value of the abrasive carrier becomes lowered,and its abrading efficiency is reduced to the point that such carriermust be discarded and a fresh carrier substituted. This is a matter ofconsiderable expense for such replacements. Additionally, the down timeof the machine and related equipment, and the time and labor lost inmaking such replacements are a serious item of expense. It is animportant feature of my present invention to greatly reduce such losses.Such improvements are produced as follows: The resilient and elasticsurface of the supplemental wheel is compressed against the abrasivesurface as I have already explained. This compression causes the surfacematerial of the supplemental wheel to penetrate around the abrasiveparticles which are themselves adhered to the abrasive carrier, so thatintimate contact between the resilient elastic surfacing of thesupplemental wheel and the carrier or the foreign material or detrituson such carrier, is produced, the abrasive particles remaining adheredto the carrier itself. The wetting of such elements as alreadyexplained, enhances the intimacy of this contact between the surfacingof the supplemental wheel and such detritus material. These operationstake place as the clearance between the surface of the supplementalwheel and the abrasive surface is falling to zero. Thus, when thelocation of maximum pressure between the supplemental wheel and theabrasive surface is reached a substantial pressure has developed betweenthe surface of the supplemental wheel and the abrasive carrier and itsdetritus material, with full expulsion of air from the area of contact,and with the production of a vacuum cup seal between the supplementalwheel and the carrier and detritus carried thereby. As the travels ofthe supplemental wheel and such carrier proceed, each elemental area ofsuch wheel commences to withdraw from the proximate elemental area ofthe carrier, and such withdrawal is produced with a sufiicient force toeffect separation of the elemental surfaces from'each other against theresistance due to such vacuum cup sealing effect. Such vacuum cupsealing effect is developed against the detritus materials between theabrasive particles which abrasive particles constitute portions of orare cemented to the abrasive carrier. Experience has shown that the"vacuum cup effect thus produced and existing between the resilient andelastic surfacing of the supplemental wheel, and such detritus material,is greater than the adherence of the detritus material to the carrier.Consequently the detritus material is torn away from the carrier itselfand such detritus material then travels circularly with the supplementalwheel until expelled therefrom by centrifugal force and dissipated inall directions.

The abrasive particles of the abrasive surface are cemented or stronglyadhered to or constitute portions of the abrasive surface. Thisadherence is much greater than the vacuum cup effect produced on suchcemented abrasive particles by the resilient elastic material of thesupplemental wheel. Consequently, as the wheel elemental area separatesfrom the proximate elemental area of the abrasive surface, the abrasiveparticles are not torn from the carrier to which they are adhered, butthey are left in their cemented or adhered relation to such carrier;Thus, only the detritus material is torn away from its condition ofbeing packed around and between the cemented abrasive particles, leavingsuch abrasive particles cemented or otherwise adhered to the carrier,the detritus material having been thus broken loose and removed frombetween the abrasive particles of the surface. Thus such abrasivesurface is renovated and renewed to its full abrasive quality.

The following function is also noted in connection with the foregoingfeature:

This cleaning or clearing operation occurs each time a given elementalarea of the abrasive surface comes into engagement with the supplementalwheel. Thus such cleaning or clearing action occurs with greatfrequency. In fact it occurs once for each abrading contact of theabrasive elemental area with the work body. For this reason the detritusmaterial is never allowed to become excessively collected on anyelemental area of the abrasive surface, and is never allowed to becomeseverely packed between the abrasive particles carried by the carrier.Accordingly, the abrasive surface of the carrier is not allowed tobecome loaded with the detritus material, but is maintained in a clean,efiicient, and highly elfective abrading condition.

Various kinds and compositions and specifications of liquids may be usedin the practice of this invention. These include, by way of exampleonly, and not as limitations, except as I may limit myself in the claimsto follow, such electronic media quality materials as cutting oil andcoolant, cutting waxes, either neat or as solutions, catalytic agents orvarious kinds, soluble oils, and various other materials of properfreedom of flow, low viscosities, and other requirements. Said materialsmay also be used either cold or hot, or of various specifiedtemperatures. Water is also frequently used for such purposes.

The yieldable, resilient, elastic surfacings of the supplemental wheelor the abrasive wheel, when used, may also be formed of variousmaterials. Such materials as natural and/or artificial rubbers, autotread rubbers, Buna rubbers, Hycar rubbers, neoprenes, and many otherswhich are wear and abrasive resistant against their contacts with theabrasive materials of the belt or the abrasive wheel surface, may beused. It is thus evident that I do not intend to limit myself to anyspecific yieldable, resilient, and/or elastic material or materials,except as I may limit myself in the claims to follow.

Other objects and uses of the invention will appear from a detaileddescription of the same, which consists in the features of constructionand combinations of parts hereinafter described and claimed.

In the drawings:

Figure 1 shows a schematic embodiment of the features of my presentinvention in a system wherein a belt travelling over a contact wheel andan idler is used, the supplemental wheel being adjustably mounted closeto that run of the belt which approaches the contact wheel (being thetop run), and provision being made for introducing 6 i the body ofliquid or spray into the location between the belt and the supplementalwheel where the clearance is rapidly falling to zero; and in the showingof this figure the contact wheel is shown as provided with a fiat orcylindrical surface of yieldable resilient, or elastic material, thesupplemental wheel being crowned and provided with a surface of abrasionresisting, resilient or elastic material and a shield to collect anyoutthrown liquid body; and in this figure there is also shown provisionfor adjustably pressing the supplemental wheel against the belt at thedesired location and with the desired pressure, as well as provision foradjusting the tension on the belt;

Figure 2 shows a section taken on the line 22 of Figure 1, looking inthe direction of the arrows; and there is shown a pump for deliveringthe liquid body material to the desired zone through a series of spraynozzles directed to that zone; I

Figure 3 shows a section taken on the line 3-3 of Figure 1, looking inthe direction of the arrows;

Figure 4 shows another embodiment of the present invention in which nobelt is used, the abrasive material being carried directly by thesurface of the abrasive wheel, or comprising a constituent of suchwheel, as when such wheel is formed of vitreous abrasive material, suchabrasive wheel being cylindrical or fiat, or contoured to conform to thework bodys section requirements or contour, whereas the supplementalwheel may be crowned as shown or contoured to correspond to the contourof the abrasive wheel, and such supplemental wheel is provided with anabrasion resisting, resilient or elastic surface to provide an area offunctioning contact with the abrasive wheel so that various of thefunctions and objectives already explained may and will be accomplished;

Figure 5 shows a view taken on the line 55 of Figure 4, looking in thedirection of the arrows;

Figure 6 shows a modified form of crowned supplemental wheel, the crownbeing rounded, and the surface of such wheel being formed or coated.with abrasion resisting, resilient, elastic material; and

Figure 7 shows an enlarged detail of the portions of Figures 1 and 4,wherein the supplemental wheel is in functional area contact with thebelt or the abrasive wheel, and this figure shows how, during the travelbetween the locations of first contacting of the supplemental wheel andsuch belt or abrasive wheel and the location of disengagement thereof,the surface of the supplemental wheel may and does yield radiallyinwardly to enable production of the desired functions and objectives.

In the drawing I have shown schematically several embodiments of mypresent invention. Referring first to Figures 1, 2 and 3, the contactwheel 10 is carried by the shaft 11, which shaft is suitably journalledin bearings. not shown. Such contact wheel usually also serves as thedriver of the system for which purpose its shaft is suitably driven atdesired speed. The direction of rotation is shown by the arrow. Suchcontact wheel is preferably surfaced with a yieldable, resilient,elastic surfacing 12, indicated by the stippling in Figures 1- and 3.

In the showing of Figures 1, 2 and 3 a belt 13 travels over such contactwheel, and also over the idler wheel 14. Such idler wheel is shown asbeing crowned, and as being shiftable towards and away from the contactwheel. To these ends the idler wheel is carried by the shaft 15 which isjournalled by the bearings 16 (only one of which is shown in Figure 1).These end bearings are guided for back and forth movement in the sottedsupports 17. Each bearing is also provided with an outwardly extendingstem 18 which extends through a stationary abutment 19. A compressionspring 20 is provided around each such stem, an adjustable abutment nut21 being threaded onto the stem to thereby compress the spring betweensuch nut and the stationary abutment 19. By this means the tensiondeveloped in the belt is forth. movements of the idler wheel necessaryduring running to produce smooth operation.

Provisions are conventionally made for ensuring proper tracking of thebelt on the contact wheel. Details of such provisions need not bedisclosed here as various such means are well known in the present art.However, it is here noted that the supplemental wheel now to bedisclosed may also serve to aid in securing or ensuring good tracking.Such supplemental wheel is schematically shown at 22. It is providedwith a shaft 23 suitably journalled by the journals 24 (only one ofwhich is shown). Preferably such journals 24 are shiftable towards andaway from the belt 13. Suitable guides for guiding such shifts are alsoprovided (not shown), but which may be similar to the guiding arranements provided for the guiding of the idler Wheel as already disclosed.Each such journal is provided with an upwardly extending stem 25 whichextends through the stationary abutment 2 6. The compression spring 27is provided on each such stem, and a nut 28, threaded onto the stemprovides means to adjust the spring urge of the wheel shaft downwardlytowards the belt. In Figure 1 I have indicated a slight depression ofthe belt produced by such down thrust of the supplemental wheel.

The supplemental wheel is so located and supported that its location ofcontact with the belt is very close to the location of entry of suchbelt onto the contact wheel periphery so that only a short travel of thebelt occurs between the supplementary wheel and the contact wheel. Thiscloseness is desirable for several reasons, including the fact that thusthe wetted surface of the belt, presently to be detailed, is thusexposed to the air and to possible loss of the liquid body throughvarious agencies such as evaporation, etc., for on y a short distanceand interval of travel before such wetted surface portion reaches thelocation at which the work body is in contact with the belt or wheelsurface.

This supplemental wheel is preferably crowned as shown in Figures 1, 2and 3; and such wheel is also preferably provided with a surfacing ofabrasion resisting, resilient, elastic material, as shown at 29, andindicated by the stippling. Accordingly the pressure of suchsupplemental wheel against the belt surface, or against the abrasivewheel surface, as in other embodiments presently to be referred to,produces an outwardly or upwardly facing V-shaped depression in the beltjust in advance of entry of such belt onto the contact wheel. Suchdepression is almost immediately afterwards rectified as the belt ridesonto the contact wheel, or in case such contact wheel is itself alsocrowned, an actual reversal of the V wi'l occur between the supplementalwheel and the contact wheel. In any case, however, it is emphasized thata strong pressure is developed between the supplemental wheel and thebelt surface at the location in advance of entry onto the contact wheel.Due to such strong pressure, and also the fact that the supplementalwheel is surfaced with abrasion resisting, resilient, elastic material,good penetration of the surfacing of such supplemental wheel into andbetween the abrasive particles on the belt surface is ensured. Suchabrasive particles are of very hard material, and are cemented orotherwise adhered to the belt surface. Accordingly, as the belt runsunder the supplemental Wheel, which is travelling at belt peripheral orlinear speed, the particles of liquid body which is on or very close tothe belt surface are forced and crowded down into strong engagement withthe belt surface, and due to the yieldable nature of the supplementalwheel surfacing such liquid body material is also carried down aroundand into strong engagement with each of the abrasive particles cementedto the belt. Thus there is forcibly applied a film of the liquid bodydirectly to each of the abrasive particles, as distinguishedfromprevious attempts to wet such abrasive particles by merely spraying themwith such liquid body material.

It is now emphasized that a further and very important difference thusexists between any such mere spraying operation and the operation hereindisclosed. This vital difference is as follows:

In the case of the effort to deliver the liquid body through the film offast moving air close to the surface of the belt or abrasive surfacewheel, the carrier by which such liquid body material must be carriedand delivered to the abrasive surface is the air blast itself,Accordingly, under such a scheme of operations such air blast carriermust itself penetrate through the air film carried close to the surfaceof the belt or abrasive wheel, in order to deliver any particles of theliquid body to such abrasive surface, since the particles of such liquidare of microscopic size, being in the form of a spray. Of themselvesthey have substantially no kinetic energy of velocity to carry themthrough the film of air travelling close to the abrasive surface.Accordingly, they never do actually wet the abrasive particles butrather they are dissipated into the surrounding atmosphere as a finemist. This fact is attested to by examina-v tion of an abrasive belt orabrasive wheel towards which, travelling at the intended high linearspeed, there has been directed a jet or spray of liquid intended to wetthe abrasive surface. Upon examining such abrasive surface afterstoppage of its travel it will be found to be dry and show no signs ofhaving been wetted by such spray or jet. On the contrary, examination ofthe abrasive surface of a belt or abrasive wheel to which has beenapplied the liquid body according to the teachings of this case it willbe found that the abrasive particles of such abrasive surfaces have beenthoroughly wetted, and that they retain such wetting for a considerableinterval of time after stoppage of the belt or wheed travel, and untildrying is produced by natural processes.

As distinguished from such air carrier method of directing the liquidbody material towards the abrasive surface the presently disclosedmethod and means acts to deliver the liquid body material to theabrasive surface by mechanical pressure developed by a sold body,namely, the supplemental wheels surface, and its physical contact withthe abrasive surface at the critical area. While it is true that a jetor spray is conveniently used to supply the liquid body material intothe zone close to the closing area as already explained, still theactual delivery of such liquid body material to its intended destinationis effected by physical pressure developed between two solid bodies. Thefact that one or both of such bodies may be and generally are surfaceswith yieldable resilient and/or elastic material does not change theunderlying principle of the operation, since solid bodies, even thoughelastic and yieldable, have very different characteristics from thoseenjoyed by gases and vapors. These facts are too well understood torequire further discussion here.

In Figures 1, 2 and 3 I have shown schematically several jets or spraynozzles 30, preferably of small orifices, all supplied by a commonmanifold 31 extending across the width of the supplemental wheel. Thesmall delivery tips of these nozzles come very close to the closingposition or line between the supplemental wheel and the belt or abrasivewheel, but evidently it is impossible to carry them exactly and finallyinto the infinitesimally thin zone which exists just before finalphysical contact between the supplemental wheel and the belt or theabrasive wheel occurs. However, due to the air conditions existing atsuch final very thin zone and the slowing down of air travel at suchzone, it has been found that excellent delivery of the liquid bodymaterial to its intended destination can be and is produced by thearrange? ments already explained.

Conveniently the liquid body material is supplied under pressure to suchmanifold by a pump, such as a centrifugal or reciprocating pump 32,drawing its supply from a source, not shown, and delivering its outputin tangential fashion as is well understood. Since the supplementalwheel is subject to slight variations of separation axially from thecontact wheel, due to vibrations and other forces, although contact isretained with the abrasive belt or with the abrasive surface of theabrasive wheel itself, and since it is desired that the nozzles 30retain their exact positions with respect to such supplemental wheel, Ihave shown such nozzles as carried by a bracket 33 which is connected toone of the shaft hearings or other suitable element in such manner thatthe manifold and nozzles always retain the desired relation to suchsupplemental wheel. Also, in order to take care of such vibrational andother adjustment changes between the supplemental and contact wheels,while retaining the nozzles in fixed relation to the supplemental wheel,I have shown the section of flexible conduit 34, such as hose or thelike, included in the line 35 connecting the pump to the manifold. Also,a valve 36 is indicated for controlling the rate of delivery of theliquid body material to its intended zone. Once the operation has beenbrought into regular balanced condition such valve may generally beclosed at least partially so as to supply the material only at such rateas may be needed to keep the abrasive surfaces properly wetted.

Since some liquid body material will inevitably be thrown by centrifugalforce from the supplemental wheel, due to its high peripheral velocityand angular velocity, I have also shown a sheet metal guard 37encircling such supplemental wheel between the locations 38 and 39 whichare close to the surface of the abrasive belt or the abrasive wheelsurface as the case may be. Any liquid body material collected by thisguard will run off at one or both ends, or may be collected inconvenient manner and re-used.

By way of illustration I have indicated a work body in the form of ametal bar 40 in pressed relation to the abrasive wheel or the abrasive'belt at a point convenient for proper manipulation of such work body.

Figures 4 and illustrate schematically an embodiment wherein theabrasive wheel itself is provided with an abrasive surface against whichthe work is pressed, there being no abrasive belt riding over suchwheel, and in this embodiment the supplemental wheel directly contactssuch abrasive wheel with provision for delivering the liquid bodymaterial to the closing space between such supplemental wheel and theabrasive wheel under conditions such as already explained. his deemedunnecessary to describe this embodiment in full detail, but forconvenience I have legended like parts of this embodiment and that ofFigures 1, 2 and 3 with like numerals, but with application of thesuffix a." The following comments are, however, proper:

In the present case, since the supplemental wheel is provided,preferably with an abrasion resisting resilient or elastic surface, andsince the abrasive wheel may be likewise provided with a resilientsurface, it is evident that pressure developed between the two wheelswill produce depression of one or both such yieldable surfaces at theirlocations or areas of contact. In the embodiment now under considerationthe supplemental wheel is shown as being crowned, and the abrasive wheelas being of cylindrical surface. Accordingly, when sufficient pressureis developed between such wheels such depression will extend completelyacross both Wheels, or that one of less width, thus producing thedesired contact between the two wheels completely across such wheels.Thus the effects which I have already detailed will be produced for thefull width of such wheels. Further, since the supplemental wheel doesnot contact a travelling surface which is approaching the abrasive wheelfrom a third, or idler wheel, it is evident that there is no limitationas to the angle at which such supplemental wheel may be set, meaningthat the axis of such supplemental wheel may be directly above the axisof the abrasive wheel, or, as in Figure 4, the axis of the supplementalwheel may actually be brought over above the descending peripheralsurface of the abrasive wheel. Such placement may be as far over asdesired, provided, only that the supplemental wheel does not interferewith the proper application of the work body 40 to the abrasive wheelssurface. Thus, with this arrangement the travel of the applied liquidbody after its application and before its coming to the work zone may bereduced to a minimum, with consequent benefits in some cases.

Figure 5 shows a view on the line 5--5 of Figure 4, looking in thedirection of the arrows, and this Figure 5 emphasizes the fact that thedepression produced in the yieldable resilient elastic surface of theabrasive wheel when its surface is yieldable or resilient, by thecrowning of the supplemental Wheel, may be carried as far across theabrasive wheel as desired by producing the necessary pressure betweenthe two wheels by the spring adjustment.

Figure 6 shows a face view of a modified form of crowning which may beused for the supplemental wheel. In this case the crowning is roundedinto a spherical segment surface, instead of being the conventionaldouble conical surface. Such rounded surface design is desirable for usein some cases.

In Figure 7 I have shown on enlarged scale as compared to previousfigures a detail of the area of contact between the yieldable, resilientelastic surface of the supplemental wheel and the abrasive belt surfaceunder the condition that the pressure exerted by the supplemental wheelagainst such belt surface is suflicient to compress the resilientelastic surfacing of such supplemental wheel enough to produce anappreciable area of contact angularly between said parts. Such area ofcontact begins at the location 41 where the supplemental wheel firstengages the belts surface, and extends to the location 42 where suchengagement terminates. The location of maximum compression of theresilient elastic surface of the supplemental wheel is at about thepoint 43. During wheel surface and belt surface travel from 41 to 43 theelastic surfacing of the supplemental wheel is penetrating deeply intothe interstices between the abrasive particles of the belt, and makinggood contact with the detritus material carried by the belt. Suchcontact is improved and rendered largely air tight by the wetting of thesurfaces, and the air is expelled from between the supplemental wheelssurface and that of the belt. Then, as the operation proceeds from thelocation 43 to the location 42 the elastic surface of the supplementalwheel is expanding or relaxing due to reduction of compression thereof,until the location 42 is reached where definite separation occursbetween such surfaces. Due to the vacuum cup engagement between thesurfaces there will actually be a small stretching of the elasticsurface material of the supplemental wheel, until a condition arrives atwhich the pull exerted on the elastic surface of the supplemental wheelis sufiicient to drag the surfaces apart, with the removal of thedetritus material as already explained in some detail.

The wetting operations herein disclosed are very different from theconventional operation of flushing the cutting tool of a machine toolunit with oil or other coolant. In such previously practised operationsthe cutting tool is not producing any operation at all comparable to thegrinding and/or polishing operations to which the present inventionrelates, and the flushing of the point of the tool as conventionallypractised is for a very different purpose and is effected in a verydifferent manner from the wetting operations herein disclosed, and whichhave to do with a completely different type of operation, namely, thatof acting on and treatmg a comparatively large surface of the work bodyas compared to the small surface, cutting away, operation performed bysuch machine tool.

I claim:

1. The. combination with an element having an abrasive surface and meansto drive said element for movement of said abrasive surface in adirection of travel towards and past a work abrading location, saidsurface being provided with fine particles of abrading material, ofmeans to wet said abrasive surface and said abrasive particles at alocation in advance of said work abrading location, comprising asupplemental wheel in peripheral engagement with the abrading surfacealong a narrow Zone of contact parallel to the axis of the supplementalwheel at said location which is in advance of the work abradinglocation, the abrasive surface and the surface of the supplemental wheeladjacent to the location of peripheral engagement aforesaid providinga'space of generally V-shape between the surfaces with the apex of suchV at the location of said peripheral zone means to journal saidsupplemental wheel for rotation on an axis extending transversely of thedirection of travel aforesaid, said supplemental wheel beingprovided'with a surface of abrasion resisting resilient material, meansto urge the supplemental wheel towards the abrading surface to therebycause the surface of the supplemental wheel to contact with and embracethe particles of abrading material at the wetting location aforesaid,said surface of the supplemental wheel travelling in the same directionas the travel of the abrasive surface at said wetting location andnozzle means having its orifice in position to deliver wetting bodymaterial to said V-shaped wetting location and between the abrasivesurface and the convex surface of the supplemental wheel, which convexsurface is approaching engagement with the abrasive surface andtravelling with a component of movement in the direction of travel ofthe abrasive surface.

2. Means as defined in claim 1, wherein the supplemental wheel iscrowned, and wherein the abrasive surface is yieldable at the locationof peripheral engagement of the supplemental wheel with such surface, tothereby allow conformity of the abrasive surface with the supplementalwheel surface at such peripheral engagement location.

3. Means as defined in claim 1, wherein the element having an abrasivesurface comprises a belt, a contact wheel and an idler wheel, the belttravelling over said two wheels with belt runs extending between the twowheels, and wherein the supplemental wheel is in periph eral engagementwith the abrasive surface of the belt at a location in advance of theentry of the belt onto the periphery of the contact wheel.

4. Means as defined in claim 3, wherein the supplemental wheel iscrowned, and wherein the contact wheel is provided with a cylindricalsurface.

5. Means as defined in claim 3, wherein the supplemental wheel iscrowned.

6. Means as defined in claim 1, wherein the abrasive surface comprisesthe peripheral surface of a wheel, and wherein the work abradinglocation comprises a 10- cation of the peripheral surface of said wheel,and wherein the supplemental wheel is in peripheral engagement with saidwheel at a location in advance of said work abrading location, andwherein the supplemental wheel urging means acts to urge the.supplemental wheel into engagement with the abrasive surface. wheel.

7. Means as defined in claim 6, wherein the peripheral surface of the.wheel is also yieldable radially of said wheel.

8. Means as defined in claim 7, wherein the Wheel surface iscylindrical.

9. The combination of an abrasive carrier having a continuous abrasivematerial carrying surface comprising a closed circuit perimeter,abrasive particles in tension resisting connection with saidsurface,means to sup port said carrier for travel of its surface in said closedcircuit perimeter of travel, said closed circuit perimeter of travelincluding a work body abrading location, together with means tocontinuously remove detritus material from the abrasive carrying surfaceof said carrier, comprising a Wheel adjacent to said carrier, said wheelbeing provided with a yieldable resilient elastic peripheral surface,and means to journal said wheel with its peripheral surface in runningengagement with the abrasive surface of the carrier.

10. Means as defined in claim 9, wherein said wheel is journalled withits peripheral surface in compressive pressure with the abrasive surfaceof the carrier.

11. Means as defined in claim 10, together with means to vary the amountof the compressive pressure of the peripheral surface of the wheelagainst the abrasive surface of the carrier.

12. Means as defined in claim 9, together with means to supply wettingagent to the location of running engagement of the peripheral surface ofthe wheel with the abrasive surface of the carrier.

References Cited in the file of this patent UNITED STATES PATENTS

